| 摘要 |
PROBLEM TO BE SOLVED: To obtain a high quality raw material for ceramics and refractories by adding a carbonaceous material to an alumina-silica-based refractory raw material such as agalmatolite or clay, especially a low grade raw material containing alkali components comprising Na and K and subsequently thermally treating the mixture. SOLUTION: This ultrafine SiC-AlN-based composite raw material powder is obtained by reducing Al2O3 and SiO2 contained in an alumina-silicabased refractory raw material with gaseous nitrogen and carbon contained in a carbonaceous material. When the alumina-silica-based refractory raw material contains K and Na components, the crystal structures of the Al2O3 and SiO2 are perfectly decomposed. Thereby, the K and Na components contained in crystals are oxidized into K2O and Na2O and evaporated off as gases. The alumina-silica-based refractory raw material includes natural minerals and synthetic minerals, and alumina-silica-containing materials such as brick scraps and industrial wastes can also be used. The temperature for heating the raw material is desirably 1,450-1,650 deg.C. |
